I looked through both of my F-4 Phantom Crew Chiefs' Handbooks, which cover F/RF-4C/D/E models, and it looks like all of these Phantoms had fuel vent line drains protruding through the bottom side of the tail cone skin roughly halfway between the rear end of the tailhook and the front edge of the drag chute door. If this is the drain you're asking about, that's what it is. The fuel vent line drain. Below the drag chute compartment there was also small metal rod protruding out an inch or so below the door and which had a small hole drilled through it. This rod was where the crew chief would attach the small, hooked drag chute door tool in order to latch the door closed after inserting (and usually having to push very hard on) the freshly-packed drag chute when post-flighting his or her jet. If you are referring to this little metal rod directly under the drag chute compartment, that isn't a drain. Just a link to the drag chute door latch mechanism. Regards, Bill Wheeler, SSgt., F-4E crew chief at Hahn AB, Germany, 1976-1978.
Hi, Gary,
I looked through both of my F-4 Phantom Crew Chiefs' Handbooks, which cover F/RF-4C/D/E models, and it looks like all of these Phantoms had fuel vent line drains protruding through the bottom side of the tail cone skin roughly halfway between the rear end of the tailhook and the front edge of the drag chute door. If this is the drain you're asking about, that's what it is. The fuel vent line drain. Below the drag chute compartment there was also small metal rod protruding out an inch or so below the door and which had a small hole drilled through it. This rod was where the crew chief would attach the small, hooked drag chute door tool in order to latch the door closed after inserting (and usually having to push very hard on) the freshly-packed drag chute when post-flighting his or her jet. If you are referring to this little metal rod directly under the drag chute compartment, that isn't a drain. Just a link to the drag chute door latch mechanism. Regards, Bill Wheeler, SSgt., F-4E crew chief at Hahn AB, Germany, 1976-1978.